Cord lock for venetian blinds



June 2 .1,, W41 W J, sTUBER coRD LOOK FOR VENETIAN BLINDS OriginalFiled'March 6] 194m 2 Sheets-Sheet 1 v PH-Run y June 24, 194317., w. J.STUBER CORD LOCK FOR VENETIAN BLINW Original Filed March 6, 1940 2Sheets-Sheet 2 w 9 w 2 v A 4 m: M in m 1 3 0 7 w J 6 a 6 v 5 w a W Y Z Ww 4. A. W W w w W Patented June 24, 1941 anti CORD LUCK FGR VENETKANBLKNDS (Priginal application March 6, 1940, Serial No. 322,6ii i.Divided and this application June 25, 1349, Serial No. 342,345

(Cl. 156 l?) 3 Claims.

This invention relates to Venetian blinds and particularly to the lockfor the elevating cords of the blind disclosed in the copendingapplication, Serial No. 322,604 of which the present application is adivision.

The object of the present invention is to provide a simple and highlyefll'cient cord lock composed of a few simple parts which will cooperateto produce quick locking and easy releasing of the elevating cords andwhich will insure against accidental slipping of the cords withconsequent dropping of the slats of the blind from their intendedelevation.

The construction and operation of the cord lock of the present inventionwill be fully disclosed hereinafter, reference being bad to theaccompanying drawings, of which:

Fig. 1 is a front elevation of the blind with the cord lock mechanismholding the slats at a predetermined elevation;

Fig. 2 is a transverse section taken on the line 2 2, Fig. 1;

Fig. 3 is a sectional plan view taken on the line 3--3, Fig. 1; and

Fig. 4 is a sectional elevation taken on the line 4-4, Fig. 2.

As shown in Fig. 1, the blind I includes the usual bottom rail 2, slats3, ladder tapes 4, 4 and elevating cords 5, 5.

The ladder tapes 4, 4 are secured at their up- 5 per ends to rockers 6,6 respectively, which are secured to a tilt shaft 1 adapted to be rockedabout the axes of aligned end pivots 8 and 9 carried by brackets iii andII respectively.

Suitable mechanism I2, operable by a tilting chain I3 is provided forrocking the shaft I and thereby setting the slats 3, 3 at any desiredangle, transversely, to the horizontal.

The pivot brackets Ii! and I I are carried by the head rail I5, which inturn, is supported on end brackets It and H. The elevating cords 5, 5pass upward from the bottom rail 2, through slots in the slats 3, 3,between the front and back tapes of each of the ladders 4, 4 to rollersor pulleys I8, I8 which are rotatably mounted in guide members i9, I9provided for the ladder tapes 4, 4 at the rockers 6, B respectively.

From the guide rollers I8, Hi the elevating cords 5, 5 pass to and undera roller Iilli which is rotatably mounted in a housing 82 carried by thebracket I I.

From the roller Hi l the elevating cords pass upwardly then over andaround the periphery of a roller Iiil which is rotatably mounted on ashaft Hi2 having its ends secured in extensions or legs 33 of a U shapedbracket iihi carried by the bracket ii. From the roller HlI the cords 5,5 extend downwardly through an opening I formed in the bottom plate ofthe head rail I 5 to be joined together at their lower ends in a commontassel 0r handle Hit, whereby raising and lowering of said tassel willeffect corresponding lowering, and raising of the bottom rail 2 and theslats 3.

The slats may be maintained at any desired elevation by a locking catchIii], see Fig. 4, which is in the form of a U shaped lever having armsIll, HI pivoted on a common pin H2 carried by the bracket Hi4 andconnected at their outer ends by a cross plate H3. The cross plate H3 isprovided with cross slits IM and the metal adjacent said slits is bentinwardly, as indicated at H5, Fig. 4, to provide teeth adjacent theperipheral face of the roller itl between which and said teeth theelevating cords 5 extend. By swinging the cords 5 to the left, as viewedin Figs. 1 and 4 and pulling said cords downwardly said cords becomereleased from the teeth N5 of the locking catch Hi1 permitting saidcatch to drop until the lower edge thereof substantially contacts withand rests upon a cross plate I It which joins the outer ends of armsIi'l, Iii and which constitute with the cross plate i IS an actuatinglever IIB for the locking latch IN]. The arms Hi, l H are pivotallymounted on a common pivot H9 carried by the bracket I M.

With the latch 9 iii released in the manner above noted the cords 5 maybe operated to raise or lower the blind, as desired. Then by swingingsaid cords t to the right as viewed in Figs. 1 and i, said cords, byreason of their passing through an opening 12%! in the cross plate H6 ofthe actuator H8, swings said actuator to the right. In doing so thecords 5 engage the teeth N5 of the locking latch i i t and while holdingthe cords in the position they have assumed while being swung to theright and leaving said cords move upwardly said cord will carry saidteeth upwardly, swinging the latch I it about its pivot and pinching thecords between said teeth and the periphcry of the roller iiiI.

Preferably the face of the roller iiiI is circumferentially grooved at"Ma for each cord 5, and these grooves are deposed in line with theholes E29, E2!) in the lever 658 through which the cords 5, 5 extend,whereby the portions 5a, 5a of the cords, between the roller iiii andthe ever H3, are maintained in substantially straight lines constitutinga definite predetermined position of the cords with respect to the teethI l5 of the locking lever l l I], when the outer free end of the latteris resting on the cross bar H6 of the lever H8, so that by slightswinging of the lever H8 to the right, as viewed in Fig. 4, the fibresof the cords 5 will catch in the teeth H5 and raise the outer end of thelever Hi] until the teeth pinch the cords against the face of the rollerHJI as a result of the relationship existing between the pivot of thelever H0 and the axis of rotation of the roller HM. As the arcuate pathdescribed by the teeth H5 intersects the arcuate surface of the rollerllll, with the cords 5, 5 disposed between the teethand the roller, thecords will be pinched by the teeth H5 against the surface of the rollerIii"! and held against further upward movement. The weight of the blindsupported by the cords 5 5 accentuates this gripping and pinchingaction.

However, due to the relationship of the axes about which the roller H3!and lever Hi3 move,

and the. relation of the arc traversed by the teeth H5 with: respect tothearc'v of the peripheral surface of the roller tilt, and due to thefact that both cord pinching surfaces are movable and rock in the samedirection about centers atone and the same side of the cords beingpinched between the two, the locking grip on: the cords is readily and:easily broken by merely pulling down.- wardly on the free ends of thecords 5, 5: because there is no hard fast jamming of the cords against afixed surfacebya single rockabl'e looking latch as is common in the"prior art.

I claim;

l. A Venetian blind structure comprising cord actuated slat elevatingmeans including a pulley for changing direction of movement of the operating cords from, horizontar to: vertical and vice versa, said pulleybeing rotatably mounted between two: substantially paralleli plate-likesupports;v alock for said cords comprising a U"- shaped lever pivoted:to said; supports at one sideof the axis of rotation of said pulley andincluding a: portion paralleling the face: of said polley and adapted toswing in a path to intersect with said pulley face to pinch said cordsthere-- between,v said portion having spaced: inwardly projecting edgesfor engaging said ropes: when the latter are swung. in. one direction intangential relation to'fsay pulley face and: ta release said ropes whenthe latter are swung in an opposite direction, and an actuator for saidlever pivoted to said supports at the opposite side of the axis ofrotation of said pulley with a transverse portion extending across saidU-shaped lever adjacent the toothed portion thereof and provided withopenings through which said ropes extend for swinging said actuator tooperate said locking lever.

2. In a cord lock for Venetian blinds, a roller over which the cordpasses and from which the cord hangs vertically, the axis of rotation ofthe roller being located at one side of the hanging portion of the cord,a locking lever rockable about an axis located below the axis ofrotation of the roller at said one side of the hanging portion of thecord, teeth on said locking lever at the opposite side of the hangingportion of the cord andv adapted to describe an arc intersecting the arcof that portion of the periphery of the roller about which the cordpasses, and a lever rockable about an axis located above the axis ofrotation of the roller and including a portion located below saidlocking lever, said lever portion having an opening through which thehanging portion ,of the cord extends in definite relation to the teethof the locking lever.

3. In a cord lock for Venetian blinds, a roller over which the cordpasses and from which the cord hangs vertically, the axis of rotation ofthe roller" being located at one side of the hanging portion of thecord, a locking'lever rockable about an axis located below the axis oirotation of the roller at said one side of the hanging portion of thecord, teeth on said lockinglever at the opposite side of the hangingportion of the cord and adapted to describe an: arc intersecting the arcof that portion of the periphery of the roller about which the cord'passes; andalever rockable about an axis located above the axis ofrotation of the roller and including a portion located below saidlocking lever and affording a rest for the outer end of said lockinglever when released from the cord, said lever portion having an openingthrough which the hanging portion of the cord extends in definiterelation to the teeth. of the locking lever.

WALTER; J STU BER.

